Aquatic invaders near Great Lakes
Asian carp infiltration could spark consumption nightmare
By John F. Bonfatti
Published April 10, 2005
Walleye season opens in May, and bass season begins in
But will anglers find the fish they covet in the years
to come as they troll or cast in lakes Erie and Ontario?
That may depend on an invisible, underwater electric
barrier the federal government is building near Chicago
to keep the latest high-profile aquatic invaders out of
the Great Lakes.
These nasty fish - called Asian carp - can weigh up to
They can jump as high as 10 feet out of the water - and
have injured boaters, jetskiers and marine biologists.
They also possess a nearly insatiable appetite - often
eating up to half their body weight each day in the microscopic
plants and animals, called plankton, that are at the base
of the Great Lakes food chain.
Observers are nervous about the impact that kind of consumption
would have on a fishery that industry analysts value at
$4 billion to $6 billion.
"It's an eating machine," Doug Stein, a charter
boat captain on Grand Island, said of the invading species.
"Imagine having a whole bunch of carp in the system
eating up everything in sight."
These invaders wait at the Great Lakes' door.
They have advanced up the Mississippi River to the Chicago
Sanitary and Ship Canal, which connects the river to the
Scientists believe the carp have come to within 22 miles
of a temporary electric barrier in the canal, and to within
about 50 miles of Lake Michigan.
A second barrier, which should last up to 20 years, is
under construction at a cost of $9.1 million and should
be ready by summer.
Once the carp get into Lake Michigan, biologists expect
it wouldn't be too long before they show up in all the
Great Lakes, including Lake Erie.
Scientists, sportsmen and environmentalists cringe at
the thought of the carp breaching the barriers.
"The worst scenario?" asked Jennifer Nalbone
with Great Lakes United, the environmental group known
for its advocacy on behalf of the lakes. "Five giant
Brought to this country 20 years ago as a means of controlling
algae, plants and parasites on catfish farms along the
Mississippi, several species of Asian carp escaped those
farms during floods in the early 1980s and 1990s. In less
than a decade, the carp have become dominant on parts
of the Mississippi and Illinois rivers, according to Pam
Thiel, who monitors invasive species for the U.S. Fish
and Wildlife Service.
"Once they establish themselves, if they are more
than 12 to 15 inches long, there's nothing out there that
can physically stuff (the carp) down their mouth,"
she said. "That means those fish can stay out there
and keep growing."
The bighead carp is the largest of the group, with some
examples growing to 4 feet long and 100 pounds.
But the silver carp has drawn the most attention, mainly
because of its spectacular leaping ability.
Thiel said many people on the river marveled at the sight
- until the leaping fish started hitting boaters and jetskiers.
She said a number of her colleagues have been hit by silver
carp, including one who went on disability due to a back
One scientist said he was hit so hard, it knocked a filling
out of his mouth, while another said a flying silver carp
broke her nose.
Officials are eager to keep the Asian carp out of the
Great Lakes because of the fear they will compete for
the food that small fish eat.
Those fish, in turn, are consumed by the larger fish
that anglers desire.
"We have a lot of other species that are plankton
feeders," said Bill Culligan with the state Department
of Environmental Conservation's Great Lakes Fisheries
unit in Dunkirk. "If (the carp) impact our forage
fish, there could be a serious impact to fish like smallmouth
bass, walleye and trout."
Charter captains and area sportsmen like Tom Marks, who
serves as the Great Lakes Sport Fishing Council's New
York director, believe the carp would do well in the lakes.
"They probably won't do quite as well because the
lakes aren't as fertile as the river," he said, "but
. . . they will expand."